Instruction manual

Why
dlJk
~rlves
need alignment?
Commodore
disk
drives
use
a
moveable
readlwrite
head that
Is
connected
through a
mechanical
linkage
to a stepper
motor.
this stepper
motor
Is
In
turn
controlled
by
the
disk
drive
microprocessor.
During
readlwrlte
activity,
the
microprocessor
moves
the
head
over
the
disk
surface
collecting
(or
writing)
data.
If
a particular
track
Isn't
where the
micropro-
cessor
thinks
It
should
be,
or
It
encounters
an
error
on
the
disk
(very
(ommon
with
protected
disks),
It
then attempts to "reallgn" the
head
by
smacking
It
against the head stop
assembly.
This
way
the
microprocessor
makes
sure
it
knows
precisely
where the
head
Is
at, then
It
attempts the
read
or
write
activity
again.
This
will
happen a
few
times
before the
microprocessor
will
declare
an
error.
The
microprocessor's
attempts to
realign
Itself
are
what
causes
drive
alignment
problems.
The
readlwrlte head, banging against the head stop,
causes
the stepper motor shaft to
slip
Inside
the stepper motor
hub.
This
causes
the head to
be
positioned to a different
location
than the
microprocessor
has
ordered.
And
you
now
have
drive
alignment
problems.
Although
the
1571
uses
a photo-electric
cell
to eliminate head
knock,
occasionally
It
will
encounter a
disk
error that
will
cause
It
to chatter
loudly.
This
is
the
sound
of
heads
going
out
of
alignment!
Using
the
1541/1571
Drive
Alignment
System
After
loading,
press
any
key
to
pass
the introduction
screen,
then
you
will
be
asked
to
select
a
drive
number.
Select
the
drive
number of the
suspect
drive.
It
Is
now
a good
Idea
to
review
the
on-screen
'Instructions,
especially
the
Safety
ar,ld
Legal
notes.
Familiarize
yourself
with
the
procedure
to
check
angnment.
Before
checking
alignment,
Insert
the
reverse
side
of
the program
disk
Into
the
suspect
drive.
This
Is
the
calibration
disk.
Follow
the
on-screen
Instructions
to evaluate the alignment
condition
of
your
drive.
If
alignment
Is
Indicated,
review
the
adjusting
,Instructions
for
your
drive
type
before attempting
It.
Make
sure
you
always
exit
the
program
with
the
(OJ
option
from
the alignment
screen
menu.
This
will
return
your
drive
to
normal
operation. '